jdk8-mips64-public/hotspot: src/share/vm/opto/regmask.cpp@c792b641b8bd (annotated)

src/share/vm/opto/regmask.cpp@c792b641b8bd (annotated)

src/share/vm/opto/regmask.cpp

Wed, 10 Sep 2008 20:44:47 -0700

author: kvn
date: Wed, 10 Sep 2008 20:44:47 -0700
changeset 767: c792b641b8bd
parent 435: a61af66fc99e
child 1907: c18cbe5936b8
permissions: -rw-r--r--

6746907: Improve implicit null check generation
Summary: add missing implicit null check cases.
Reviewed-by: never

 /*
  * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 #include "incls/_precompiled.incl"
 #include "incls/_regmask.cpp.incl"
 #define RM_SIZE _RM_SIZE /* a constant private to the class RegMask */
 //-------------Non-zero bit search methods used by RegMask---------------------
 // Find lowest 1, or return 32 if empty
 int find_lowest_bit( uint32 mask ) {
   int n = 0;
   if( (mask & 0xffff) == 0 ) {
     mask >>= 16;
     n += 16;
   }
   if( (mask & 0xff) == 0 ) {
     mask >>= 8;
     n += 8;
   }
   if( (mask & 0xf) == 0 ) {
     mask >>= 4;
     n += 4;
   }
   if( (mask & 0x3) == 0 ) {
     mask >>= 2;
     n += 2;
   }
   if( (mask & 0x1) == 0 ) {
     mask >>= 1;
      n += 1;
   }
   if( mask == 0 ) {
     n = 32;
   }
   return n;
 }
 // Find highest 1, or return 32 if empty
 int find_hihghest_bit( uint32 mask ) {
   int n = 0;
   if( mask > 0xffff ) {
     mask >>= 16;
     n += 16;
   }
   if( mask > 0xff ) {
     mask >>= 8;
     n += 8;
   }
   if( mask > 0xf ) {
     mask >>= 4;
     n += 4;
   }
   if( mask > 0x3 ) {
     mask >>= 2;
     n += 2;
   }
   if( mask > 0x1 ) {
     mask >>= 1;
     n += 1;
   }
   if( mask == 0 ) {
     n = 32;
   }
   return n;
 }
 //------------------------------dump-------------------------------------------
 #ifndef PRODUCT
 void OptoReg::dump( int r ) {
   switch( r ) {
   case Special: tty->print("r---");   break;
   case Bad:     tty->print("rBAD");   break;
   default:
     if( r < _last_Mach_Reg ) tty->print(Matcher::regName[r]);
     else tty->print("rS%d",r);
     break;
   }
 }
 #endif
 //=============================================================================
 const RegMask RegMask::Empty(
 # define BODY(I) 0,
   FORALL_BODY
 # undef BODY
 
 );
 //------------------------------find_first_pair--------------------------------
 // Find the lowest-numbered register pair in the mask.  Return the
 // HIGHEST register number in the pair, or BAD if no pairs.
 OptoReg::Name RegMask::find_first_pair() const {
   VerifyPairs();
   for( int i = 0; i < RM_SIZE; i++ ) {
     if( _A[i] ) {               // Found some bits
       int bit = _A[i] & -_A[i]; // Extract low bit
       // Convert to bit number, return hi bit in pair
       return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+1);
     }
   }
   return OptoReg::Bad;
 }
 //------------------------------ClearToPairs-----------------------------------
 // Clear out partial bits; leave only bit pairs
 void RegMask::ClearToPairs() {
   for( int i = 0; i < RM_SIZE; i++ ) {
     int bits = _A[i];
     bits &= ((bits & 0x55555555)<<1); // 1 hi-bit set for each pair
     bits |= (bits>>1);          // Smear 1 hi-bit into a pair
     _A[i] = bits;
   }
   VerifyPairs();
 }
 //------------------------------SmearToPairs-----------------------------------
 // Smear out partial bits; leave only bit pairs
 void RegMask::SmearToPairs() {
   for( int i = 0; i < RM_SIZE; i++ ) {
     int bits = _A[i];
     bits |= ((bits & 0x55555555)<<1); // Smear lo bit hi per pair
     bits |= ((bits & 0xAAAAAAAA)>>1); // Smear hi bit lo per pair
     _A[i] = bits;
   }
   VerifyPairs();
 }
 //------------------------------is_aligned_pairs-------------------------------
 bool RegMask::is_aligned_Pairs() const {
   // Assert that the register mask contains only bit pairs.
   for( int i = 0; i < RM_SIZE; i++ ) {
     int bits = _A[i];
     while( bits ) {             // Check bits for pairing
       int bit = bits & -bits;   // Extract low bit
       // Low bit is not odd means its mis-aligned.
       if( (bit & 0x55555555) == 0 ) return false;
       bits -= bit;              // Remove bit from mask
       // Check for aligned adjacent bit
       if( (bits & (bit<<1)) == 0 ) return false;
       bits -= (bit<<1);         // Remove other halve of pair
     }
   }
   return true;
 }
 //------------------------------is_bound1--------------------------------------
 // Return TRUE if the mask contains a single bit
 int RegMask::is_bound1() const {
   if( is_AllStack() ) return false;
   int bit = -1;                 // Set to hold the one bit allowed
   for( int i = 0; i < RM_SIZE; i++ ) {
     if( _A[i] ) {               // Found some bits
       if( bit != -1 ) return false; // Already had bits, so fail
       bit = _A[i] & -_A[i];     // Extract 1 bit from mask
       if( bit != _A[i] ) return false; // Found many bits, so fail
     }
   }
   // True for both the empty mask and for a single bit
   return true;
 }
 //------------------------------is_bound2--------------------------------------
 // Return TRUE if the mask contains an adjacent pair of bits and no other bits.
 int RegMask::is_bound2() const {
   if( is_AllStack() ) return false;
   int bit = -1;                 // Set to hold the one bit allowed
   for( int i = 0; i < RM_SIZE; i++ ) {
     if( _A[i] ) {               // Found some bits
       if( bit != -1 ) return false; // Already had bits, so fail
       bit = _A[i] & -(_A[i]);   // Extract 1 bit from mask
       if( (bit << 1) != 0 ) {   // Bit pair stays in same word?
         if( (bit | (bit<<1)) != _A[i] )
           return false;         // Require adjacent bit pair and no more bits
       } else {                  // Else its a split-pair case
         if( bit != _A[i] ) return false; // Found many bits, so fail
         i++;                    // Skip iteration forward
         if( _A[i] != 1 ) return false; // Require 1 lo bit in next word
       }
     }
   }
   // True for both the empty mask and for a bit pair
   return true;
 }
 //------------------------------is_UP------------------------------------------
 // UP means register only, Register plus stack, or stack only is DOWN
 bool RegMask::is_UP() const {
   // Quick common case check for DOWN (any stack slot is legal)
   if( is_AllStack() )
     return false;
   // Slower check for any stack bits set (also DOWN)
   if( overlap(Matcher::STACK_ONLY_mask) )
     return false;
   // Not DOWN, so must be UP
   return true;
 }
 //------------------------------Size-------------------------------------------
 // Compute size of register mask in bits
 uint RegMask::Size() const {
   extern uint8 bitsInByte[256];
   uint sum = 0;
   for( int i = 0; i < RM_SIZE; i++ )
     sum +=
       bitsInByte[(_A[i]>>24) & 0xff] +
       bitsInByte[(_A[i]>>16) & 0xff] +
       bitsInByte[(_A[i]>> 8) & 0xff] +
       bitsInByte[ _A[i]      & 0xff];
   return sum;
 }
 #ifndef PRODUCT
 //------------------------------print------------------------------------------
 void RegMask::dump( ) const {
   tty->print("[");
   RegMask rm = *this;           // Structure copy into local temp
   OptoReg::Name start = rm.find_first_elem(); // Get a register
   if( OptoReg::is_valid(start) ) { // Check for empty mask
     rm.Remove(start);           // Yank from mask
     OptoReg::dump(start);       // Print register
     OptoReg::Name last = start;
     // Now I have printed an initial register.
     // Print adjacent registers as "rX-rZ" instead of "rX,rY,rZ".
     // Begin looping over the remaining registers.
     while( 1 ) {                //
       OptoReg::Name reg = rm.find_first_elem(); // Get a register
       if( !OptoReg::is_valid(reg) )
         break;                  // Empty mask, end loop
       rm.Remove(reg);           // Yank from mask
       if( last+1 == reg ) {     // See if they are adjacent
         // Adjacent registers just collect into long runs, no printing.
         last = reg;
       } else {                  // Ending some kind of run
         if( start == last ) {   // 1-register run; no special printing
         } else if( start+1 == last ) {
           tty->print(",");      // 2-register run; print as "rX,rY"
           OptoReg::dump(last);
         } else {                // Multi-register run; print as "rX-rZ"
           tty->print("-");
           OptoReg::dump(last);
         }
         tty->print(",");        // Seperate start of new run
         start = last = reg;     // Start a new register run
         OptoReg::dump(start); // Print register
       } // End of if ending a register run or not
     } // End of while regmask not empty
     if( start == last ) {       // 1-register run; no special printing
     } else if( start+1 == last ) {
       tty->print(",");          // 2-register run; print as "rX,rY"
       OptoReg::dump(last);
     } else {                    // Multi-register run; print as "rX-rZ"
       tty->print("-");
       OptoReg::dump(last);
     }
     if( rm.is_AllStack() ) tty->print("...");
   }
   tty->print("]");
 }
 #endif

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/regmask.cpp@c792b641b8bd (annotated)

src/share/vm/opto/regmask.cpp